Plumbers, pipe fitters, electricians, fire sprinkler fitters, steam fitters, and the like all use motor-driven tools at job sites to cut and thread pipe. Pipe threading machines are heavy (200 pounds or more), bulky machines, which, after they have been used, frequently are covered with oil. To safely move such machines about the job site, and from the job site to a pickup truck and vice-versa, two men are required. A single strong man may be able to move such machines, but only with the significant risk of back injuries or other injuries if the machine should slip from his grasp and fall. In addition, it is nearly impossible to avoid somewhat rough handling of the machine in the process of loading it into a truck, whether two men or one man attempts to undertake such loading. As a result, parts of the machines may be broken or damaged.
Typically, once the machine is at the job site, only a single person uses the machine; so that if it is necessary to move it from one position to another at the job site, the difficulty of manipulating and moving the heavy, bulky machine described above, once again is encountered. To avoid Workmen's Compensation claims and to facilitate the delivery, movement and return of such machines to and from job sites, most contractors send two workmen to the job site to effect the unloading, moving and loading of such machines, even though only one workman may be required at the job site. If only one workman is required at the job site, the second workman then must return to a different job site. The recovery for the wages of the second workman for this time must be made by the contractor, if his business is to remain profitable.
A manufacturer of pipe threading machines has developed a pair of wheels interconnected by an axle, with an upstanding pipe located on the axle midway between the wheels. The pipe is inserted into the pipe machine, which then is clamped onto the pipe. The machine then can be wheeled about from one point to another. To stand it up on its legs, however, requires two men to safely set the machine up. In addition, if the machine is to be loaded into a pickup truck, or unloaded from a pickup truck, it also must be lifted by two men (or wrestled in a dangerous manner by one man) in the same way as if the wheels were not present. In fact, the additional weight of the wheels further compounds the handling problem mentioned above, rather than providing a solution to it.
In the past, various devices have been developed for creating combined functions, such as a truck or cart and a table in a single unit. Four patents, disclosing such devices, are the patents to Allen No. 704,426; O'Dell No. 1,828,434; Pealer No. 2,178,605; and Sherman No. 4,565,382. The Allen patent is directed to a combination wheeled cart or litter carrier with a single large wheel located at its mid-point. Handles are provided at each end to permit two persons to roll and steer the cart over a surface. When a fixed location or semi-permanent location for the cart is located, four legs are folded down (much in the manner of a card table) to stabilize the cart and turn it into a table or stand. There is nothing in this patent, however, which suggests transferring a heavy object from a pickup truck to a lower surface in a manner which permits one person to do a job which typically requires two persons.
The patents to O'Dell, Pealer and Sherman all are directed to combined tables and hand trucks (O'Dell and Sherman), or a portable stand (Pealer) in which wheels are used in one mode of operation to move the device about, and in which various parts are moved to provide a flat table surface when rolling movement of the device no longer is required. Once again, there is nothing in any of these patents to suggest a device for loading and unloading heavy objects into and from a pickup truck by a single person, where two or more persons normally have been required.
Three other patents, Hamrick No. 2,784,004, Lehrman No. 3,804,432, and Geschwender No. 4,220,346, disclose hand trucks or dollies with various types of accessory folding members or extensions for creating a table. These devices, however, are not constructed for the purpose of facilitating the movement, loading and unloading of bulky, heavy objects by a single person.
It is desirable to provide a device for allowing a single person to move, load and unload heavy, bulky objects, such as pipe threading machines, which is simple to use, relatively inexpensive, and which overcomes the disadvantages of the prior art devices.